Just using `check` as a prefix to various keywords would lead to too many
ambiguities in the parser (notably in contracts, where you can have an empty
requires list followed by `check ensures ...` or a `check requires ...`. With
a lookahead of 1, it's difficult for the parser see which rule should apply.
Hence, the lexer will perform itself the lookahead and emit a proper token
(`CHECK_ENSURES` or `CHECK_REQUIRES` respectively).

David Bühler authored 6 years ago and Virgile Prevosto committed 6 years ago

Asserts are both evaluated and used as hypotheses afterwards.
Checks are only evaluated, but are not used as hypotheses: they must not affect
the analyses.

(blind make headers from specifications)

- Fix Value/Value#5
- Fix Value/Value#14

Some case studies (e.g. dyad) use some ugly casts from fd_set_t which lead
to the analysis stopping too early.
Changing the representation of fd_set_t should also help it better conform to
the standard (since a fd_set_t should be able to hold FD_SETSIZE elements).

[Ptests] preserve LOG after STDOPT directive

See merge request frama-c/frama-c!2073

This is absolutely not a sneaky attempt to relaunch a build (now that OCI seems
in better shape) pushing a nearly empty commit.